Connection structure, flexible tube and connection method

A flexible tube comprising:

• a flex configured to demarcate a space that houses contents;
• a first pipe member in a cylindrical shape, including a first fixing unit capable of being fixed to anther member on an outer peripheral surface on a first end side in a rotational central axis direction, the first pipe member being integrated with an end of the flex on a second end side in the rotational central axis direction;
• an inner layer blade configured to cover the flex and a side closer to the second end than the first fixing unit of the first pipe member;
• a resin layer configured to cover the inner layer blade and the side closer to the second end than the first fixing unit of the first pipe member;
• an outer layer blade configured to cover the resin layer;
• and
• a second pipe member in a cylindrical shape, including
• a two-stage structure including
• a first part having an inside diameter capable of inserting a part on the first end side of the first pipe member, and
• a second part having an inside diameter capable of inserting a part of the first pipe member covered with the resin layer and the outer layer blade,
• a second fixing unit capable of being fixed to the first fixing unit, the second fixing unit being provided on an inner peripheral surface of the first part, and
• a positioning unit configured to determine a position with respect to the first pipe member in the rotational central axis direction,
• wherein the first pipe member is inserted into the second pipe member to determine their positions with respect to each other by the positioning unit,
• the first and second fixing units are fixed to each other, and
• the outer layer blade and the resin layer are pressed and fixed to the first pipe member by the second part.

A connection method for a connection structure including:

• a first pipe member in a cylindrical shape, including
• a first fixing unit capable of being fixed to another member, the first fixing unit being provided on an outer peripheral surface on a first end side in a rotational central axis direction,
• a housing section in a tubular shape connected on a second end side in the rotational central axis direction, and
• an area closer to the second end side than the first fixing unit, the area being covered with an outer layer of the housing section;
• and
• a second pipe member in a cylindrical shape including
• a two-stage structure including
• a first part having an inside diameter into which a part on the first end side of the first pipe member is inserted, and
• a second part having an inside diameter capable of inserting a part of the first pipe member covered with the outer layer,
• a second fixing unit capable of being fixed to the first fixing unit, the second fixing unit being provided on an inner peripheral surface of the first part, and
• a positioning unit configured to determine a position of the second pipe member with respect to the first pipe member in the rotational central axis direction, the method comprising:
• inserting the first pipe member into the second pipe member to determine their positions by the positioning unit;
• fixing the first and second fixing units to each other;
• and
• pressing and fixing the outer layer to the first pipe member by the second part through reduction of the second part in diameter.